The invention relates to a magnetic disk which comprises a silicon substrate and a magnetic layer deposited on the substrate and consisting of a binder, magnetic particles and an abrasion-resistant material, and to a method of making such a magnetic disk, where a substrate is provided and a layer comprising at least one binder and magnetic particles is deposited.
High capacity magnetic disks used at present comprise substrates, preferably of aluminum, aluminum-magnesium or silicon, and a magnetic layer that is deposited thereon and preferably of a 1 .mu.m thickness, comprising a magnetic particle-filled resin. To make sure that the magnetic disk is able to resist the effect of the hard magnetic head of ceramic material which drags over the disk in the start/stop phase the resin is additionally filled with aluminum oxide particles amounting to approximately 2 percent by volume of the layer. Actually, the magnetic head does not drag on the resin directly but on the aluminum oxide particles serving as a support. In principle, such a deposit would satisfy all requirements provided the adhesion of the aluminum oxide particles in the resin matrix is very high. However, this does not apply; in fact, during the operation of the disk a knocking-out of aluminum oxide particles is frequently revealed. The consequence of this knocking-out is that the disk is subjected to increased abrasion in all those places where aluminum oxide particles are knocked out, and that the hard aluminum oxide particles placed on the disk surface contribute to a wear of the disk surface and of the magnetic head. This finally leads to a premature failure of the system consisting of magnetic disk and magnetic head. This problem is encountered as early as in functional tests after the termination of disk production, or when the disk is used at the customers' place, therefore it has caused up to now serious disturbances of production, and high maintenance costs.